Conventional serpentine fin machines make strips of fins by infeeding a flat sheet of metallic strip stock and outputting a series of metallic strips having corrugations therein. There are many uses for corrugated fin strips, particularly for vehicle components such as radiator, heater core, evaporator, and condenser fins, among others. The typical fin machine generally works by feeding the continuous length of strip stock between at least one pair of form rollers having interleaved teeth to bend the stock and form corrugations (fins).
During the operation of a fin machine, the strip stock may wrap up around a form roller. Strip stock wrapping up around form rollers can severely damage the rollers.
To prevent this problem, fin machines use a wrap-up detector to detect the wrap-up of strip stock around the form rollers. The typical wrap-up detector includes an electrical conductive probe positioned adjacent the form rollers at a sensing position. The probe is connected to an electrical circuit having a resistive sensitive relay. When the strip stock, which is electrically grounded, wraps up around a form roller, it contacts the probe causing the electrical circuit to ground out. The relay detects the grounding condition and immediately disables the fin machine and enables an alarm. To restart the fin machine, the operator must first move the probe away from the sensing position and then clear the strip stock obstruction. The operator should then move the probe back to the sensing position prior to enabling the fin machine.
A problem with typical wrap-up detectors is that if the probe is disconnected from the relay or is misplaced from the sensing position then a wrap-up condition will not be detected thereby resulting in the destruction of the form roller.